When a trading agreement is sent to you for signing, a blue sign-off button should be visible at the top right of your screen.
If you can only view the trading program but cannot sign the trading program off, then this might be due to your user permissions. When your trading partner invites you to Collaborator, they have the ability to choose whether you are able to only view the trading programs, or you also have the ability to sign off trading programs. If you expect to be able to sign off a plan within Collaborator, please contact your trading partner for them to change this setting.
When signing off a trading program, the trading program reference must be typed into the text box before you can proceed. Take care when typing this plan reference - it must match exactly including capitalisation of letters.